New documentary ‘Unacknowledged’ claims to expose years of cover-ups within the US government over the alleged truth of alien visitations of Earth being kept hidden from the public.

The film is directed by Michael Mazzola and follows Dr Steven Greer, who is a major player in the so-called disclosure movement, which is calling for an end to an alleged truth embargo which ensures the cover up continues.

The extensive documentary touches on the death of Monroe, which it suggests was a murder coordinated by the CIA, because of an alleged affair with president John F Kennedy.

Dr Greer has produced an alleged top secret CIA memo written two days before the star was found dead on on August 5, 1962, in Brentwood, Los Angeles, California.

He claims it shows how she was wire tapped by the agency which had concerns about her liaison with the president.

The alleged memo suggests JFK told her he had seen evidence of “things from outer space” at a secret air base and officials panicked that she may disclose this at a press conference.

Dr Greer claims the memo was referring to the remains of the alleged infamous Roswell flying saucer crash said to have landed in the New Mexico desert in July 1947.

On his website, Dr Greer states: “We have a number of smoking gun documents, including a wiretap of Marilyn Monroe the day [sic] before she died, which has never been declassified.

“She was threatening to hold a press conference to tell the world what Jack Kennedy had told her during pillow talk about having seen debris from an extraterrestrial vehicle at what the document calls a ‘secret air base’.”

“She was murdered for this.”

Dr Greer is well respected among some UFO circles, but has been branded a hoaxer by more sceptical investigators, something he vehemently denies.

However, he has been behind some extraordinary claims in the past, including stating that the US government has obtained technology from aliens that could provide the world with free energy, but suppresses it to ensure the fossil fuel industry can thrive.

He also claims to be able to summon UFOs and that he once did this in conjunction with the French ministry of defence.